Touch Probe with Nomad 833

Hello everyone. It’s been a long time since I’ve been present in this forum. Life in general happened and had not the mental clarity to devote time to CNC learning. Things are going back to normal and I’m staring to take on projects that I had to put on the back burner for a while. Since my vacuum setup is all set and done and working great, I’m moving into zeroing with accuracy. Touch probes interest me and I want to see if I can adapt one to my Nomad 833 Classic.
I’m interested in and just purchased this:

It will require for me to use Universal GCode Sender (UGS) to use the probe. So far so good.

When it arrives I need to connect a cable to the probe port of the board inside my Nomad and another one to the ground of the power supply unit. I’m not electronically inclined but are very handy and open to exploration. I opened my Nomad and think I found where everything should go but have a few questions. Here is the video that the manufacturer of the probe has online that shows how to connect the probe to the CNC’s Arduino based board.

This is what I have in my Nomad 833 Classic


There are two cables. One white and one green. Which of the two should I splice the probe cable to?.


I think I can screw the ground cable to the third screw down from the top. I think that is the “ground” symbol. Would that work?.

I want to bring these two cables to some sort of connector attached to the case so I can connect and disconnect the probe easily. Any ideas, suggestions or warnings are welcome, please. I don’t want to do something stupid if it’s not worth it.

Glad to be back.


Be very careful on that side of the power supply! If there are any charged capacitors it might bite you. The machine may already be grounded you could check that probably with a VOM if you have one.
If your going to splice the probe anyways why not splice both of them and run them where you need them accordingly?

I see. Thanks. Will be careful.

Yeah, that video isn’t applicable to the Carbide Motion controller. Carbide 3D routed the Positive and Negative of the probe switch to the white Molex connector that you show with the 12-pin header. They have already done all the hard wiring work for you.

As Roger said, you are better off splicing both the green and white wire and running both wires to your probe; the green one to the banana plug/triquerta and the white one to the alligator clip (I am basing the colors off the post here, which is for the Shapeoko 3 but that is supposed to use the same basics of the Carbide Motion controller). You could verify that by doing a continuity test between the pins of the probe and the pins of the feed_hold; if the right pin of each has continuity, then they are both ground.

I would definitely stay away from the power supply.

I see. That would be perfect. I was wondering if the two cables going to the Probe connector were indeed one for the probe and one for the ground. If this is indeed true for the Nomad too, that’s what I will do. Thank you. Can someone confirm that this wiring is correct for the Nomad 833 too?.

Good morning. My touch plate should be arriving today. I’m still not sure if wiring another probe to the board is a good idea on the Nomad or not. Would love to hear from Carbide if possible. Also, probe and ground wiring is as in the photo?.

It looks correct.
However as a side note, a lot of the machines are grounded. So using the spindle as the ground typically works best, and the touch plate to be the actual probe connection. You can check with a VOM if the spindle is grounded.

@rogwabbit Thank you for all your help. What I’m trying to setup is a probe, not only a touch plate. My mistake on how I wrote my previous post. I know nothing about electronics. Please forgive my lack of knowledge if this is too basic of a question. The device I’m getting requires me to plug a wire to the “probe” port of the Nomad board and another wire to the ground of my CNC. From the responses I’m getting here I think I have to plug the green wire to the banana plug that goes to the probe block and the ground wire with the alligator clip to the white wire or ground. My idea would be to just splice the two Triquetra wires to the green and white wires respectively. Sorry to continue to ask the same question but I’m a little nervous to damage my Nomad. I’m guessing I’m voiding the warranty and that from this point on I’m on my own. I’m aware of this and willing to take the risk but I’m trying to make the most informed actions I can by asking for opinions and information. Thank you all.

The touchplate and Probe all work with the same probe pin.
The pin has a very tiny pull up voltage and when grounded (shorted out) it triggers the code in the controller to stop motion.
There is very little you can do to damage it with the exception of:

  1. Large static electricity to the probe pin.
  2. Some stray voltage to the probe pin. (i.e you touch a battery or something like this.)

I’m just saying that if the machine’s spindle is grounded, the probe ground wire will work better there and the actual probe wire on the part that will make contact with the bit.

If the 2 wires touch it just sends the stop signal to the controller it’s not going to hurt anything.

Hope that clears up some concerns?

If you are not getting a response from Carbide 3D on this thread, maybe try emailing/calling them?

I have a Shapeoko 3, not a Nomad, but I am guessing that the Nomad uses this Probe input for the tool length probe. You might want to hook both up in parallel, and not just replacing the current probe wires with the triquerta wires. This should be fine, but you will want to ensure that your PROBE wire (banana plug) is kept away from any sort of grounding when not in use with the triquerta, or you could get accidental PROBE signals sent to the controller.

@rogwabbit Thank you very much for all your help and patience. Yes it does clear things up. I will post findings as soon as I have everything connected. Do you think I can use the same type wire to do my splicing as the wires that are in the Nomad?. Thanks again.

All is set. I have my Nomad 833 zeroing with precision via Universal GCode Sender. I now have to figure out how to keep that zero data and use it in Carbide Motion. I’d love to keep the tool length probe functionality from CM. I’ve tried turning off my Nomad after zeroing keeping the bit at the zero position. Turning it on again, opening CB and going to settings and turning “Shaepoko Has Homing” to “False”, right?. I’m a little confused with the wording on label “Shaepoko Has Homing”. Does it mean that it already has home position and not to home, in which case “True” would be the right setting, or that it has homing enabled in which case “False” would be my choice. What I’m looking for is to zero with Universal GCode Sender and then use that zero data in Carbide Motion. Possible?. Would be awesome if I could just use CB for all the probing. Why is it not possible?. I’m sure there are good reasons, just curious.

Nope. Carbide Motion will overwrite the EEPROM settings for WCS 54. So you can’t really do it that way.
On the other hand can’t you issue the probe commands manually in carbide motion? I have not tried that yet but I think it should work.